Round the handle over until the ends rest inside the rolled rim of the can or biscuit cutter and you are ready to solder the handle in place.
As the soldering is the most important part of the tin work the next two chapters are devoted to it.
=The Sugar Scoop.=—A useful sugar or flour scoop may be easily made from a small or large can in exactly the same manner as the biscuit cutter, except that the can is cut off slanting instead of square, Fig. 15. The edges of the scoop should not be turned or folded but should be left as cut so as to form a sharp cutting edge that will easily enter sugar or flour. The handle is shaped in exactly the same manner as that of the biscuit cutter.
SOFT SOLDER—SHEET TIN—THE PROCESS OF SOLDERING—HEATING APPARATUS—ELECTRICAL SOLDERING COPPERS—THE COMMON SOLDERING COPPER—FLUXES—TINNING THE COPPER—HEATING
=Soft Solder.=—When two or more pieces of metal are joined together with a metallic cement, they are said to be soldered.
Sheet tin, of which cans are constructed, is always soldered with soft solder, a mixture of lead and tin, usually 50 per cent. lead and 50 per cent. tin.
This solder is usually supplied in wire or bar form at any hardware or electrical supply house.
Copper, brass, bronze, iron, silver, gold, and practically any metal except aluminum may be soldered with soft solder.
=Sheet Tin.=—Sheet tin, so-called, really consists of a thin sheet of iron coated on both sides with tin. This coating of tin serves several purposes. It enables the solder to adhere easily; it prevents the iron from rusting; and when the sheet tin is made up into can form, the tin coating protects the contents of the can from chemical action on the iron.
=The Process of Soldering.=—Soft solder is applied to the metal to be soldered in a molten state and this operation requires considerable heat. When heat is applied to metal it usually oxidizes that metal; that is, dirties it.
Solder will not adhere to oxidized metal. The metal must be protected with a coating called a flux while being soldered. Soldering paste, soldering fluid or “killed acid,” resin, paraffin, heavy oils, and vaseline all serve as fluxes, some better than others. The soldering paste is by far the best, as will be shown later.